Compressor unit



R. T. CHEW COMPRESSOR UNIT I Nov. 30, 1965 6 Sheets-Sheet 1 Filed July16, 1962 FIG.

V REC.

CO N D.

EVA P.

INVENTOR: ROY T CHEW Nov. 30, 1965 R. T. CHEW 3,220,639

COMPRESSOR um'r Filed July 16, 1962 i e Sheets-Sheet 2 ROY T. CHEWATT'YS WWI Nov. 30, 1965 R. 1'. CHEW COMPRESSOR UNIT Filed July 16, 19626 Sheets-Sheet 3 FIG. 5

I 28' @41 Y- Q INVENTOR.

ROY T. CHEW TT'YS Nov. 30, 1965 R. T. CHEW 3,22

COMPRESSOR UNIT Filed July 16, 1962 6 Sheets-Sheet 4 F|G.8 H

I I I I I E I 5- I I I E l I I I I I T I I 55 '1 P531 I I L-- I I l I:--54 I I I I I L INVENTOR: ROY T. CHEW ATT'YS R.-T. CHEW COMPRESSORUNIT Nov. 30, 1965 6 Sheets-Sheet 5 Filed July 16, 1962 INVENTOR. ROY T.C H E W ATT YS Nov. 30, 1965 R. T. CHEW 3,220,639

COMPRESSOR UNIT Filed July 16, 1962 6 Sheets-Sheet 6 INVENTOR; ROY T.CHEW ATT'YS 3,220,639 CONIPRESSOR UNIT Roy T. Chew, 11322 S. MichiganAve., Chicago, Ill. F iied July 16, 1962, Ser. No. 209,945 16 Claims.(Cl. 230-208) This invention relates to refrigeration compressors andparticularly to improvements in the construction of such devices withthe object of improving their operating efficiency and simplifying therefrigeration systems in which they are used.

Conventional refrigeration systems generally involve extraneous heatexchange devices and connections, in addition to the usual condenser andevaporator, for assuring gasification of liquid entrained in the coldgas returning from the evaporator and, in the case of multistagecompressors, for intermediate cooling of the gas as it passes from onestage of compression to another. This usually requires extra valves andbranch conduit connections, as Well as the external heat exchangedevices themselves, and not only complicates the refrigeration systemcircuitry but also adds considerably to the system cost.

Therefore, the main objects of this invention are to provide an improvedcompressor unit that will simplify the construction of refrigerationsystems and reduce the cost thereof; to provide an improved unitarycompressor-heat exchanger construction for use in refrigeration systems;to provide a compressor housing incorporating therein a labyrinth ofcontiguous, parallel passages for refrigerant flow, from the evaporatordirectly to the compressor and from the compressor to the condenser, soarranged that counterflow of the refrigerant through contiguous passageseffects a positive heat transfer to the incoming cold gas to assureconversion of the refrigerant into a completely vaporized state beforeentering the compression cylinder; to provide such a compressorconstruction having a self contained suction accumulator and oilseparator and a discharge muffler means; to provide a compressor unitarrangement of this kind for use in either a single-stage singlecylinder compressor construction or a multi-stage compressor havingeither a single cylinder or a multiple cylinder construction; and toprovide an improved compressor unit of this kind of such simple form asto make its manufacture exceedingly practical and economical and itsoperation highly facile and eflicient. v

Specific embodiments of this invention are shown in the accompanyingdrawings in which:

FIGURE 1 is a diagrammatic perspective view illustrating the labyrintharrangement of fluid flow passages as they would generally be embodiediu'the housing of a two-stage single cylinder compressor constructedinaccordance with this invention;

FIG. 2 is a schematic perspective view showing the piston arrangementfor a two-stage single cylinder, compressor construction embodying afluid flow passage system such as that illustrated by FIG. 1.

FIG. 3 is a top plan view of a two-stage, single cylinder compressorhousing constructed in accordance with this invention;

FIG. 4 is a transverse sectional view, of the second-stage end of thehousing body shown in FIG. 3, taken on the plane of the line 44 of FIG.3;

FIG. 5 is a transverse sectional view, of the first-stage end of thehousing body shown in FIG. 3, taken on the plane of the line 55 of FIG.3;

FIG. 6 is a transverse sectional view, of the secondstage end header ofthe housing shown in FIG. 3, taken on the plane of line 66 of FIG. 3; Y

taken on the plane of the line 7-7 of FIG. 3;

United States Patent Pat ent ed Nov. 30, 1965 FIG. 8 is a schematic viewshowing a labyrinth passage arrangement for a two-stage, two cylindercompressor constructed in accordance with this invention, the viewillustrating the interconnection of the passages with the first andsecond compression stages of the two cylinders;

FIG. 9 is a plan view of a two-stage, two cylinder compressorconstructed in accordance with this invention and embodying the internalpassage scheme of FIG. 8;

FIG. 10 is a right-hand end view of the body block, for the compressorshown in FIG. 9, taken on the plane of the line 1010 of FIG. 9;

FIG. 11 is a transverse sectional view, of the righthand header shown inFIG. 9, taken on the plane of the line 1111 of FIG. 9; and

FIG. 12 is a transverse sectional view of the header for a singe-stagesingle-cylinder compressor constructed in accordance with thisinvention.

The essential concept of this invention involves the incorporation intoa compressor housing of a heat transfer flow passage labyrinth for thecontiguous, reversely directional flow of a refrigerant to, through, andfrom the compressor, the passageways also being arranged to provide asuction accumulator function and a discharge mufiier function all withinthe said housing.

A combination compressor-heat exchanger unit embodying the foregoingconcept comprises a housing H with one or more cylinder-pistoncomponents CP and wherein is incorporated a labyrinth L affordingcircuitous refrigerant flow between an inlet port I and an outlet port0.

The adaptation shown in FIGS. 1-7 is a two-stage single cylinderconstruction (called single-cylinder because the first and second stagepistons are axially aligned); the adaptation shown in FIGS. 811 is atwostage multiple cylinder construction; and the adaptation shown inFIG. 12 is a single-stage single cylinder construction. The following isa detailed description of each of these adaptations.

In the adaptation of FIGS. 1-7 the housing H is shown as a block 14 ofrectangular form more or less centrally of which are located the opposedfirst and second stage cylinders 15 and 16 wherein reciprocate theinterconnected pistons 17 and 18 (FIG. 1). The block 14 mounts the usualheaders 19 and 20 respectively between which and the block 14 areinterposed the respective valve plates 21 and 22.

The housing block 14, along its upper portion, is formed with thelabyrinth L comprising the five, contiguous, parallel passages a, a, b,c, and d-d' for directing the flow of the refrigerant between the inletport I and the outlet port 0, via the hereinafter-described chambers inthe headers 19 and 20 and in the opposed ends of the housing block 14,as determined by the reciprocation of the pistons 17 and 18 in therespective cylinders 15 and 16.

As most clearly indicated in FIG. 3, the labyrinth passages a, a, b, c,and d-d' extend lengthwise of the block 14, parallel with axes of thecylinders 15-16, and are separated by comparatively thin walls to permitthe most facile heat transfer between the fluids flowing through thesepassages.

The passes a and a, in the block 14, are connected with the inlet port Ithrough a relatively large chamber 25 formed in the left hand end of theblock 14, into which chamber extends a nozzle 30 from the inlet port I(FIG. 4). At the opposite end of the block 14 the Walls of thesepassages a and a extend to the end of the block and the passagesconnect, through openings 23 and 24 in the valve plate 21, withcommunicating chambers 23 and 24 in the right-hand header 19 opposed tothe larger cylinder 15 ant. (See FIG. 7). From the cylinder 15 thecompressed 3 gas is discharged into the chamber 26 and thence into thepassage b through valve plate passage 26 (FIGS. 3 and 7). The walls ofpassage 12 extend the entire length of the block 14 and the passage bleads through an opening 27 in the valve plate 22 into a chamber 27 inthe header 20, opposed to the cylinder 16 wherein occurs thesecond-stage compression of the refrigerant (See FIG. 6). From cylinder16 the compressed gas is discharged into a chamber 28 in the header 20and thence through valve plate opening 28 into the labyrinth passage(FIG. 6). From the passage c the compressed refrigerant enters thechamber 29, formed in the first stage end of the block 14, and thenceacross the cylinder 15 to the opposite side of the block where it entersthe labyrinth passage d connecting with the outlet port 0 (FIG. As shownthe chamber 29 is relatively large in volume and occupies a considerableportion of the end area of the block for a purpose which will hereafterbe explained.

The valve plates 21 and 22 mount conventional flappertype intake anddischarge valves. As shown, the plate 21 has concentric series of intakeand discharge openings, 31 and 32, communicating respectively with thechamber 2324 and the chamber 26 in the header 19 (FIG. 7). Flow throughthese openings 31 and 32 is controlled by the respective flapper valves33 and 34, as influenced by the suction and compression strokes of thepiston 17 in the cylinder 15. Similarly, the valve plate 22 hasconcentric series of openings 36 and 37 communicating respectively withthe chambers 27 and 28 in the header 20 (FIG. 6). Refrigerant flowthrough these openings is controlled by the flapper valves 38 and 39 asinfluenced by the suction and compression strokes of the piston 18 inthe cylinder 16.

It will now be seen that the cold gas inlet, at the second stage end ofthe compressor, leads through the nozzle 30 directly to the chamber 25which extends the entire width of the compressor body and across the endof the second stage cylinder 16. This chamber 25 is thus relativelylarge in volume and function as a built-in suction accumulator and oilsepartor for the first stage cylinder. Also the chamber 25, togetherwith the passages a and a and the chambers 23' and 24', serves as amufller to cut down suction noise. The nozzle 30 serves to direct theincoming cold gas and liquid to the bottom of the accumulator chamber 25and to prevent its short-circuit from the inlet directly to the passagesa-a.

Similarly the chamber 28, which receives the second stage of compressedgas, and the chamber 29, at the first stage end of the compressor body,serve as a built-in discharge mufiler to eliminate pulsation and silencethe discharge from the compressor outlet 0. Furthermore, the chamber 29,which extends across and partially surrounds the cylinder 15,'serves asa heat-sink to rapidly heat, the valve plate 21, upon starting up of thecompressor, and thereby additionally safeguard the first stage inletvalve against slugging by liquid refrigerant possibly being carried overfrom the initial heat exchanger or suction accumulator chamber 25.

Thus my improved compressor construction not only provides its owninternal subcooler and intermediate gas desuperheater, whereby a greatlyincreased efliciency of operation is had, but also provides an automaticand built-in, or self-contained, suction accumulator, oil separator, anddischarge muffler means. The oil separator function is provided by thelegs of the chamber 25. which have small drain holes leading to thecompressor crank case.

In the adaptation shown in FIGS. 8-11 the housing H is a rectangularblock 41 in which is journalled a crank shaft 42 disposed more or lesscentrally of the longer dimension thereof. The crank shaft 42 isconnected to the opposed pair of first-stage pistons 43-43 and theopposed pair of second-stage pistons 44-44 which operate in therespective cylinders 45-45 and 46-46. As shown, the block 41 mounts theusual opposite end headers 47 and 48 with the interposed valve plates 49and 50.

The housing block 41, transversely in the upper portion, is formed witha labyrinth L comprising five contiguous, parallel passages f, f, g, gand h, for directing the flow of refrigerant between the inlet port Iand the outlet port 0, via the hereinafter described chambers in theheaders 47 and 48 and the ends of the block 41, as determined by thereciprocation of the pairs of pistons 43-43 and 44-44 in the cylinders45-45 and 46-46 respectively.

As most clearly indicated in the schematic FIG. 8, the parallel passagesf and f are connected at their ends by cross passages i and i' builtinto the body casting and the passages g and g are connected medially byan opening i in the wallbetween them. The inlet port I enters mediallyof the passage 1 and the outlet port 0 is connected medially of thepassage h. As shown, these passages are separated by comparatively thinwalls to permit the most facile heat transfer between the fluids flowingthrough them.

For convenience of description, the two-stage doublecylinder compressorillustarted in FIGS. 8 to 11 inclusive is shown with the two first stagepistons 43-43 opposed to each other and with the two second stagepistons 44-44 likewise opposed but out of phase. Thus one end of thecompressor is the same as the other, with headers and valve platesdiffering only as to hand, and the description of one end will suflicefor both. It will be understood, however, that any suitable arrangementof stages and cylinders may be employed and still utilize the internalheat exchange, accumulator, and muffler system herein described.

As shown in FIGS; 8 to 11, the passage 1 0nd f lead to the communicatingchambers 51 and 52 in each of the headers 47 and 48 opposed to thelarger cylinders 45-45 wherein the first-stage compression of therefrigerant is effected. The refrigerant is then discharged through therespective header chamber 53 to the passage g (FIG. 11). The passage gopens, through a restricted area j (FIG. 8) to the passage g which,adjacent its ends, leads to the respective chambers 54 (FIG. 11) in theheaders 47 and 48 opening to the respective smaller cylinders 46-46wherein the second-stage compression of the refrigerant is effected. Thecompressed refrigerant is then discharged through the respectivechambers 55 to the valve plate opening 55 leading to the passage h andthe outlet port 0 (FIGS. 10 and 11. As shown in FIG. 8 the solid linesindicate the fluid flow at one end of the compressor and the brokenlines indicate the fluid flow at the other end. Each end, however, isidentical with the other except for hand.

The valve plates 49 and 50 are of the conventional flapper-valve type.As most clearly shown in FIG. 11, each such plate has concentric seriesof openings 56 and 57 communicating respectively with the chamber 51-52and the chamber 53 in the header 47. Refrigerant flow through theseopenings is controlled by the respective valves 58 and 59 as influencedby the suction and compression strokes of the respective pistons 43-43in the cylinders 45-45. Also, as most clearly shown in FIG. 11, each ofthe valve plates 49 and 50 has a second series of concentric openings 61and 62 communicating With the respective chambers 54 and 55 in theheaders 47., Refrigerant flowthrough these openings is controlled byvalves 63 and 64 as influenced by the suction and compression strokes ofthe pistons 44-44 in the cylinders 46-46. Thus, as shown in FIGS. 8 to11 inclusive, pistons 43 and 44 comprise the first and second stagecompression means at one end of the compressor which means is 180 out ofphase with the compression means at the opposite end of the compressor.

In the adaptation shown in FIG. 12 the housing H is a cylinder block(not completely shown) centrally of which is a single cylinder andpiston means, not shown, of conventional form, the end of the cylinderbeing closed by a header 67 wherein is formed the labyrinth L. Thelabyrinth L comprises contiguous passages k, l and m, concentricallyarranged around the axis of the cylinder for directing the refrigerantflow between the inlet port I and the outlet port 0, as determined bythe reciprocation of the piston in its cylinder.

As with the other adaptations, these passages k, l and m are separatedby comparatively thin walls to permit the most facile heat transferbetween the refrigerant flowing in opposite directions through therespective passages. The passages have decreasing radial width from thepassage k inwardly to accommodate the decreasing volume between theinlet and outlet.

The inlet port I and the outlet port 0 are located near the adjacentends of the respective passages k and m. The passage 1 leads to thevalve plate inlet openings 68. The discharge openings 69 in the valveplate open to a central chamber n which, in turn opens into one end ofthe passage m. The openings 68 and 69 are controlled by conventionalflapper-type valve mechanism in the header plate, (not completely shownhere) of a form comparable to that indicated in FIGS. 6 and 7. To theextent here shown, such a valve plate has the concentric series ofopenings 68 and 69 communicating respectively with the passage l and achannel 71 leading from the chamber n to the passage m1. Refrigant flowbetween these series of concentric passages is controlled by the valves72 and 73 respectively shown by the broken line outwardly concentricwith the openings 68 and by the full line outwardly concentric with thedotted series of openings 69. In this compressor arrangement therelatively large area of the passage k, adjacent the inlet 1, serves asa suction accumulator and heat exchanger" for heating and gasifying anyliquid entrained with the incoming cold gas.

In refrigeration systems provision has to be made for shunting the hotrefrigerant flow from the compressor housing outlet 0 to the inlet I soas to temporarily bypass the refrigeration equipment when the demand forthe refrigerant drops below a certain level, i.e. when the dischargeback pressure on the compressor builds up to a predetermined amount. Tothat end the passage d in the adaptation of FIGS. 1-7, opens into anauxiliary passage d' (FIGS. 3 and 4), leading to the suction accumulatorchamber 25. A conventionual pressure relief valve, not shown, can besuitably disposed in the passage d to control flow therethrough. For theadaptation shown in FIGS. 8-11 such a pressure relief valve can bearranged to connect between the passages f and h, exteriorly of theblock 41, as indicated in dotted outline 74 in FIG. 8. For theadaptation shown in FIG. 12 such a conventional pressure relief valvecan be arranged to bridge the inlet and outlet ports I and O.

In each of these adaptations the labyrinth passages are so arranged, inrelation to each other and to the openings to and from a compressioncylinder, that the refrigerant flow to the cylinder is exposed to thewarming influence of the refrigerant flow from that cylinder.

In the adaptation shown in FIGS. 1-7 this juxtaposed counter flow isindicated in FIGS. 1 and 3. Here the saturated liquid refrigerant, beingdrawn from the evaporator by the suction of the first-stage piston,enters' the inlet I and dump into the accumulator chamber 25 from whichit traverses the passages a and a in the direction of the arrows shownin these two figures. Between these passages a and a is the intermediategas flow through passage b, from the first stage of compression to thesecond stage. The second stage more-highly compressed refrigerant, as ahot gas, is discharged from the cylinder 16 to the passage c, thence tothe muffler chamber 29 and then transversely across the first stage endof the block 14 to the outlet port 0.

Thus, it is apparent that the comparatively cold refrigant flowingthrough the passages a and a is successively warmed by the counter flowof the warmintermediate gas and the hot gas successively discharged fromthrough these several passages and transversely across the ends of theblock 14, insures the requisite conversion of any liquid, in theentering cold refrigerant, into a completely vaporous condition so as topreclude all possibility of non-compressible liquid being introduced into the compressor valves.

In operation the flow path through the combination compressor-heatexchanger unit of the structure shown in FIGS. 1-7 is as follows:

From the inlet port I the refrigerant is directed by the nozzle 30 (FIG.4) to the bottom of the adjacent leg portion of the chamber 25 and overinto the more remote portion thereof en route to being drawn into thepassages a and a, as indicated by the arrows in FIG. 4. At the oppositeends of the passages a and a, the action of the first-stagecylinder-piston unit 15-17 draws the refrigerant into the communicatingchambers 23 and 24 and into the cylinder through the valve openings 31.The refrigerant is then pressured out through the valve openings 32 intothe chamber 26 for entrance into the passage b, as indicated by thearrows in FIG. 7.

By action of the second-stage cylinder-piston unit 16- 18 therefrigerant is drawn from the passage b into the chamber 27 and throughthe valve openings 36 into the cylinder 16 from which it is pressuredthrough the chamber 28 into the passage 0 as indicated by the arrows inFIG. 6. From the passage 0 this highly-compressed, hot gas refrigerantis pressured through the muffling chamber 29 transversely across thefirst-stage end of the block '14 to the outlet port 0 as indicated bythe arrows in FIG. 5.

Since the refrigerant will pick up some oil from the compressioncylinders, small drain holes 76 (FIG. 4) are formed in the legs of theaccumulator chamber 25 to drain into the crank case 77. This arrangementprovides an automatic and built-in oil separator.

In operation the flow path through the improved compressor constructionshown in FIGS. 8-11 is as follows:

From the inlet port I the refrigerant enters medially of the passage 1and flows oppositely to and then through the passage i and i, in therespective ends of the block 41, to the passage f, as shown by thearrows in FIGS. 8 and 10. From the opposite ends of the passage f thealternating suction of the first-stage units 43-45, 43'45', causes therefrigerant to be drawn into the communicating chambers 51-52 in therespective headers 47 and 48 and thence through the valve openings 56into the cylinders 45-45. From these cylinders the gas is dischargedinto the chamber 53 for entrance into the passage g, as shown by thearrows in FIGS. 8 and 1.

By virtue of the alternating action of the respective second-stagecylinder-piston units 44-46 and 44-46', the refrigerant entering thepassage g is drawn through the transverse bafie passage 1' and into theadjacent end of the passage g. The alternating action of thesesecondstage units draws the refrigerant into the respective cylindersand then discharges the refrigerant into the chamber 55, in therespective headers 47, for discharge through the passage h to the outletport 0, as shown by the arrows in FIGS. 8 and 11.

In operation the flow path through the compressor unit structured asshown in FIG. 12, is as follows:

From the inlet port I the suction stroke of the piston causes therefrigerant to enter the passage k and to travel around to the passage lwhere the refrigerant is drawn into the cylinder through the valveopenings 68. The compression stroke of the piston then forces therefrigerant out through valve openings 69 into the chamber n and thechannel 71 and thence through the passage in to the outlet port 0.

It will now be seen that my invention is applicable to substantially anyform of refrigeration compressor construction' and in" any case, byutilizing the heat of compression to warm the cold gas, within thecompressor itself, the lnvention provides a means for effecting greateroperating efliciencies for both the compressor and the refrigerationsystem in which it is installed.

The main advantages of this invention reside in the structuralarrangement of the compressor unit whereby a built-in suctionaccumulator and heat-exchanger is provided to lessen the possibility ofliquid entrained in the cold gas, from damaging the intake and dischargevalves; in the fact that the suction accumulator arrangement also mayfunction as a suction mufiler to dampen suction noise; in thearrangement of the flow passages within the compressor whereby the hotcompressed gas is delivered first to a built-in discharge mufiiersection and thence to the compressor outlet so as to preventtransmission of discharge noise; in the arrangement in a two-stagecompressor whereby the discharge mutfier section of the compressorpassages also serves as part of the built-in heat exchanger for warmingthe cold gas from the evaporator before it enters the first stage ofcompression; and in the internal heat-transfer arrangement whereby, in atwo stage compressor, the cold gas passages also serve as anintermediate gas cooler or desuperheater to increase the efiiciency ofcompressor operation.

Further advantages of my invention will be found in the fact that in atwo stage compressor embodying the invention the compactness of theconstruction, in relation to capacity, provides a unit that is capableof low temperature operation with high efficiency and with lower powerconsumption and motor size than prior devices of like capacity; in thefact that my improved compressor reduces the need for extraneous heattransfer arrangements, other than the usual condenser and evaporator;and in the fact that the improved compressor permits simplification andconsiderable reduction in cost of the refrigeration system in which itis employed.

Although several embodiments of this invention have been herein shownand described it will be understood that details of the structures shownmay be altered or omitted without departing from the spirit of theinvention as defined by the following claims:

I claim:

1. A compressor comprising a housing having spaced individual inlet andoutlet ports for refrigerant fluid, cylinder-piston compression means insaid housing, individual inlet and outlet valve means for controllingthe flow of refrigerant into and out of the cylinder-piston compressionmeans, and a flow passage labyrinth formed wholly within the body of thehousing exteriorally of the cylinder-piston compression means andcomprising separate contiguous flow passages arranged in counterflowheat exchange relation with each other for connecting the inlet andoutlet ports with said compression means by way of respective ones ofsaid valve means.

2. A compressor housing as set forth in claim 1 wherein an enlargedchamber portion is formed in the fluid flow path between said inlet andthe said labyrinth to provide a suction accumulator section.

3. A compressor housing as defined by claim 1 wherein thecylinder-piston compression means comprises first and second stagecompression units, valve means are provided for each of said units, andsaid labyrinth includes a passage leading from the valve means of thefirst stage unit to the valve means of the second stage unit and in heattransfer relation with a passage leading from said inlet to the valvemeans of the first stage unit.

4. A compressor housing as set forth in claim 3 wherein the compressionunits are axially parallel and the labyrinth passages are disposedparallel to the axes of the 0nd stage valve meansand communicatinguninterruptedly with said inlet port, A

(b) first channel means in said housing connecting said first chamberwith the intake valve means of the first stage compression unit,

(c) passage means in said housing arranged in heat exchange relationwith said first channel means and connecting the discharge valve meansof the first stage compression unit with the intake valve means of thesecond compression unit,

(d) a second chamber in said housing communicating with the dischargevalve means of the second stage compression unit, and second channelmeans leading from said second chamber to said outlet port in heatexchange relation with said first channel means,

6. A compressor construction as defined in claim 5 wherein the first andsecond stage compression units are axially aligned, and the firstchannel means and said passage means are parallel with the axis of thecompression units.

7. A compressor constructed according to claim 5 wherein the first andsecond stage compression units are axially aligned, and the said secondchamber is located adjacent the first stage valve means.

8. A compressor construction according to claim 5 wherein the first andsecond stage compression units are axially aligned and operate fromopposite ends of said housing, and means is provided for controlleddirect communication between said second chamber and said first chamber.

9. The compressor construction defined in claim 5 wherein the first andsecond stage compression units are axially parallel, and the firstchannel means and said passage means are parallel with the axes of thecompression units.

10. The compressor construction defined in claim 9 wherein the first andsecond stage compression units communicate with a common header, and thefirst and second chambers are at the same end of the housing.

11. A compressor construction as defined in claim 9 wherein the housinghas opposed sets of first and second stage compression units and thelike units of the two sets are axially aligned, the first and secondstage units of each set communicating with a respective common headerand the two headers being at opposite ends of said housing, the firstand second chambers for each set of compression units are the respectiveend of the housing, and the first channel means and the passage meansand the said inlet and outlet ports are common to both sets ofcompression units.

12. A compressor comprising (a) a housing having spaced inlet and outletports,

(b) a cylinder-piston compression component incorporated in the housingand including first- .and secondstage compression units,

(c) a refrigerant flow passage labyrinth incorporated in the housingexteriorly of the cylinder-piston compression component and providing aplurality of contiguous parallel passages (1) one pair of said passagesbeing cross connected for joint communication with the inlet port andthe first-stage compression unit,

(2) a third passage being interposed between the said one pair ofpassages and interconnecting the firstand second-stage compressionunits,

(3) and a fourth passage disposed in heat transfer relation with one ofthe said pair of passages and connecting the second-stage unit with theoutlet port, and

(d) valve means for each of said compression units for controlling theHow of refrigerant between the ports successively through the said pairof passages and the third and fourth passages.

13. A compressor as set forth in claim 1 wherein the cylinder-pistoncompression means is a single-stage unit and the flow passage labyrinthis arranged generally concentrically of the axis of the said compressionmeans.

14. A compressor for gaseous fluids comprising a housing having acylinder-piston compression means therein, intake valve means anddischarge valve means for controlling the fiow of said fluid into andfrom said compression means, and a cold gas inlet port and a hot gasoutlet port on said housing, said housing having (a) first flow passagemeans therein for connecting said inlet port with said intake valvemeans, and (b) separate flow passage means Within said housing forconnecting said discharge valve means with said outlet port, said firstflow passage means and said separate flow passage means extendingside-by-side Within said housing and in counterfiow heat transferrelation With each other.

15. A compressor for gaseous fluids comprising a housing having firstand second stage compression units therein, intake and discharge valvemeans for each of said compression units for controlling the flow ofsaid fluid into and from the respective unit, a cold gas inlet port anda hot gas outlet port on said housing, said housing having therein (a) afirst flow passage means for connecting said inlet 'port with the intakevalve means of the said first stage compression unit,

(b) a conduit connecting the discharge valve means of the first stagecompression unit With the intake valve means of the second stage unit,and

(c) a separate flow passage connecting the discharge valve means of saidsecond stage unit with said hot gas outlet port,

said first flow passage leading from the cold gas inlet port beinggenerally in contiguous counter-flow heat transfer relation with thesaid conduit and the said separate flow passage leading to the hot gasoutlet port.

16. A compressor as defined by claim 15 wherein the first flow passageand the said separate flow passage each includes a chamber portionproviding a suction accumulator section and a discharge muffier sectionrespectively.

References Cited by the Examiner UNITED STATES PATENTS 2,761,391 9/1956Johnston 103-203 X LAURENCE V. EFNER, Primary Examiner.

JOSEPH H. BRANSON, JR., Examiner.

1. A COMPRESSOR COMPRISING A HOUSING HAVING SPACED INDIVIDUAL INLET ANDOUTLET PORTS FOR REFRIGERANT FLUID, CYLINDER-PISTON COMPRESSION MEANS INSAID HOUSING, INDIVIDUAL INLET AND OUTLET VALVE MEANS FOR CONTROLLINGTHE FLOW OF REFRIGERANT INTO AND OUT OF THE CYLINDER-PISTON COMPRESSIONMEANS, AND A FLOW PASSAGE LABYRINTH FORMED WHOLLY WITHIN THE BODY OF THEHOUSING EXTERIORALLY OF THE CYLIN-